Wrestling with Canon 400D file numbering.

I bought some used CF cards a while ago and never used them until the day it snowed (unusual for my area). I had left all my camera gear in the car the night before and just pulled the CF card out to grab the photos via a USB card reader, as my hands were too full to carry the camera bag in.

So, seeing snow, walking past the car and pulling a camera out without a CF card inserted meant I went to the backup CF card… this screwed up my file numbering.

From _MG_3111.CR2 I jumped to _MG_7589.CR2. Not thrilled but not life-and-death, just quite annoyed. I searched around and read a lot of forums saying it really can’t be done but I was determined to ‘fix’ it and get back to a number more indicative of my actually shot count.

WHY?

I like having a shot counter, even if not exact, as a handy guide to make rough calculation of how many “keepers” I’m taking, as a percentage. It makes me feel better about my photography hobby by reinforcing that I am learning something even on those days where I’ve struggled. I have a good idea about how many photos I’m taking in a session and what my storage card requirements are for my typical photo outings.

I’ve learned the tricks to the file numbering system. I have succeeded in getting my file numbering back to where I want it.

RTFM. The answers do exist in the manual.

The manual explains the Continuous, Auto-Reset and Manual Reset options. The key behaviours to keep in the back of your mind are:

• Continuous will keep the numbering going even when you insert a different card. If the new card has files with a higher number, the camera may continue from that higher number. (I don’t know in which situations this doesn’t happen, so ‘may’ could mean ‘almost always will’).
• Auto-Reset will reset numbering every time a card is inserted. Importantly, it resets the folder numbering too. This is the silver bullet!
• Manual Reset will create a new, sequentially numbered folder and re-start the file numbering. This can be ueful down the track if it happens again.

Quick notes:

• “IMG_” prefix on files indicates sRGB colour space, “_MG_” indicates Adobe RGB
• “.CR2″ is Canon’s newer RAW filetype. Previously “CRW”.
• Numbering is continuous across file types. If you change from JPG to RAW and back the numbers continue incrementing. The camera does not keep different counters for each file format.
• The last ‘correct’ numbered file I had was _MG_3111.CR2 which I duplicated as _MG_3211.CR2 to make space for the almost 100 photos I took in the ‘7000 range’ until I reset the numbering. I’ve now returned to those photos and renumbered them.

How to revert to your old numbering scheme:

1. Mount the CF card on the computer and decide what folder number (100CANON, 101CANON, etc) and what file number you want to get back to. Make sure you have saved all the photos you want to keep.
2. Turn camera to Auto-Reset.
3. Insert CF card. This will bring you back to 100-0100.
4. Format CF card. This will clear any spurious folders causing trouble later on.
5. For each folder number increment, select ‘Manual Reset’ from the menus. (If you’re happy with 100CANON, skip this).
6. Copy the highest number image BACK to the CF card. If it’s a JPG you can do it via the camera software, otherwise put it back in the USB reader. (I dropped _MG_3211.CR2 into 100CANON)
7. Set camera to Continuous numbering mode.
8. Reinsert CF card if removed.

To check the process worked take a new photo and review it on the LCD. Press ‘Display’ if the numbering isn’t shown. “100-3212″ equates to /100CANON/_MG_3212.CR2 for a RAW photo in Adobe RGB colour space.